// import 'jquery/dist/jquery.min.js'
(function ($) {
  $.fn.extend({
    Scroll: function (opt, callback) {
      if (!opt) var opt = {};
      var oo;
      var _this = this.eq(0).find("ul:first");
      var lineH = _this.find("li:first").height(), //23
        line = opt.line ? parseInt(opt.line, 10) : parseInt(this.height() / lineH, 10),
        speed = opt.speed ? parseInt(opt.speed, 10) : 7000, //卷动速度，数值越大，速度越慢（毫秒）
        timer = opt.timer ? parseInt(opt.timer, 10) : 7000; //滚动的时间间隔（毫秒）
      if (line == 0) line = 1;
      var upHeight = 0 - line * lineH; //-总高度
      ScrollUp = function () {
        _this.animate({
          marginTop: upHeight // <li>的margin-top
        }, speed, function () {
          for (i = 1; i <= line; i++) {
            _this.find("li:first").appendTo(_this);
          }
          _this.css({
            marginTop: 0
          });
        });
      };
      var timerID = function () {
        oo = setInterval("ScrollUp()", timer);
      };
      timerID();

    }
  });
})(jQuery);
